Turbulence Burner With Vortex Structures

ABSTRACT

A fuel burning device includes a tubular combustion cylinder open at opposing first and second ends. A fuel inlet pipe has a first end extending through the first end of the combustion cylinder partially into the combustion cylinder and a second end extending outside of the combustion cylinder. The fuel burning device also includes a burner head connected to the first end of the fuel inlet pipe and an orifice connected between the burner head and the first end of the fuel inlet pipe. The burner head is structured and arranged so that combusted fuel discharged at the second end of said combustion cylinder has reduced CO and NOx emissions.

FIELD OF THE INVENTION

The invention relates to a device and a method of subjecting fuel/airpremix to turbulent and vortex air currents to reduce carbon monoxide(CO) and oxides of nitrogen(NOx) emissions.

BRIEF SUMMARY OF THE INVENTION

An object of the invention is to provide a fuel burner that reduces COand Nox emissions.

Another object of the invention is to subject fuel/air premix to anaturally aspirated pattern of turbulent air having a curvilinearretrogradation and areas of helicoidal vortex currents of air toeliminate CO while further reducing NOx emissions.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the invention will become moreapparent after reading the following detailed description of thepreferred embodiment of the invention, given with reference to theaccompanying drawings, in which:

FIG. 1 shows a front view of a combustion cylinder according to a firstembodiment;

FIG. 2 shows a front view of a combustion cylinder according to a secondembodiment;

FIG. 3 shows a front view of a combustion cylinder according to a thirdembodiment;

FIG. 4 shows a top view of the combustion cylinder of FIG. 3;

FIG. 5 shows a front view of a combustion cylinder according to a fourthembodiment;

FIG. 6 shows a top view of the combustion cylinder of FIG. 5;

FIG. 7 shows a front view of a combustion cylinder according to a fifthembodiment;

FIG. 8 shows a top view of the combustion cylinder of FIG. 7;

FIG. 9 shows a front view of a combustion cylinder according to a sixthembodiment;

FIG. 10 shows a top view of the combustion cylinder of FIG. 9;

FIGS. 11 and 12 show the combustion cylinder of FIG. 9 rotated 90° and180°, respectively, with respect to a longitudinal axis of the cylinder;

FIGS. 13 and 14 illustrate a front and top view, respectively, of aseventh embodiment having a multiple burner head;

FIGS. 15 and 16 illustrate a modification of the multiple burner headembodiment with the addition of external vortex fins;

FIGS. 17 and 18 illustrate a front and top view, respectively, of aneighth embodiment with the burner head raised so that the nozzle capslots 10 are outside the cylindrical air guide; and

FIGS. 19 and 20 illustrate a front and top view, respectively, of aninth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A fuel burner as shown in the first embodiment of FIG. 1 includes atubular combustion cylinder 1 open at a first extremity 2 and a secondextremity 3. A fuel inlet pipe 5 projects slightly into the combustioncylinder and connects to a hollow air mixer body 6. An orifice 7communicates from the fuel inlet pipe 5 into the air mixer body 6.

The air mixer body 6 has a proximal end and a distal end. The air mixerbody 6 has three primary air inlet holes 8 at the proximal end. One ofordinary skill in the art would recognize that the number and size ofsuch holes may be varied in relation to the size of the orifice 7. Thedistal end of the air mixer body 6, farthest from the first extremity 2,terminates in a hemispherical nozzle cap 9. The cap 9 has seven nozzlecap slots 10. The number and area of the slots may be varied by oneskilled in the art in relation to the size of the orifice 7 and theprimary air inlet holes 8.

Primary ignition of fuel at the nozzle cap slots 10 creates a circularpattern of flame adjacent to an inner wall 4 of the combustion cylinder1. The combusted fuel discharges at the second extremity 3. Since theair mixer body 6 is positioned at the first extremity 2 of thecombustion cylinder 1, an unregulated, turbulent forced air effectdevelops. In addition, the exterior of the air mixer body 6 and theinner wall 4 together define a secondary area of unregulated, turbulentair for combustion. This turbulent forced air effect increases thepressure at the primary air inlets 8 and reduced CO and NOx emissionresult.

The air mixer body 6, primary air inlet holes 8 and nozzle cap slots 10may be referred to in totality as a type of burner head. Commerciallyengineered burner heads of this type are typically engineered to yield7,500 British Thermal Units (Btu) at 11 inches water column (w.c.)supply pressure for propane gas in free air burn. The embodiment in FIG.1 permits an orifice size producing 25,000 Btu at the same supplypressure of propane. As appreciated by one of ordinary skill in the art,reference to propane as a fuel is illustrative without any intent tolimit the types of fuel, which may be combusted in this burner withreduced CO and NOx emissions.

Reduced CO and NOx emissions are obtained by each of the embodiments ofthe invention. The second embodiment shown in FIG. 2 illustrates amoveable assemble bracket 11 that is attached to the exterior of thecombustion cylinder 1 and the fuel inlet pipe 5. The manner ofattachment and movement may vary without limiting the scope of theinvention. The bracket 11 is adjustable to enable the air mixer body 6to be positioned closer to the second extremity 3 of the combustioncylinder 1. When the air mixer body 6 is closer to the second extremity3, the pressure at the primary air inlet holes 8 increases, so that theresultant combustion reduces CO and NOx emissions even further than inthe embodiment of FIG. 1.

The third embodiment illustrated in FIG. 3 and FIG. 4 shows the fuelinlet pipe 5 communicating with the air mixer body 6 through a threadedchoke adjuster shaft 12. FIG. 4 is a view of the embodiment from thesecond extremity 3 through the combustion cylinder 1 toward the firstextremity 2.

As seen in FIG. 3, a choke adjuster disk 13 with mating thread isattached to the choke adjuster shaft 12. The choke adjuster disk 13creates a venturi effect as it is regulated. Such regulation also variesthe degree of turbulence of secondary combustion air. This embodimentcan be operated with varying percentages of excess air, typicallyranging from 3% to 20% for various applications and at various altitudesof sea level. Regulation of the choke adjuster disk 13 also slows thespeed of combustion gas through the combustion cylinder 1, so that COand NOx emissions are further reduced as compared to the embodiment ofFIG. 1.

The fourth embodiment as illustrated in FIG. 5 and FIG. 6 shows aturbulence disk 14 attached to the exterior of the air mixer body 6.FIG. 6, similarly to FIG. 4 is a view of the embodiment from the secondextremity 3 through the combustion cylinder 1 toward the first extremity2. In this embodiment, two different zones of air pressure in theregulated turbulent secondary combustion air develop after primaryignition. One zone is above and one below the turbulence disk 14.

In the embodiment of FIGS. 5 and 6, a pattern of turbulence with acurvilinear retrogradation develops in the secondary combustion airupstream of the ignition area of the nozzle cap slots 10. Although thepattern of turbulence occurs, flame stability is maintained. Inaddition, positive pressure at the primary air inlet holes 8 isincreased and a negative pressure develops at the nozzle cap slots 10.These changes in pressure improve flame lift-off above the nozzle capslots 10, so that CO is practically eliminated while NOx emission ismaintained at a reduced level.

The fifth embodiment as illustrated in FIG. 7 and FIG. 8 shows a hollowcylindrical air guide 15 attached to the fuel inlet pipe 5 terminatingclosest to the second extremity 3 in an air guide aperture 16, with FIG.8 being a same view as FIGS. 4 and 6 as noted above. The exterior of theair mixer body 6 and interior of the cylindrical air guide 15 define anarea of secondary combustion. The interior of the cylindrical air guide15 confines the pattern of turbulence in the secondary combustion air atthe ignition area of the nozzle cap slots 10, so that the pressureincreases further at the primary air inlet holes 8 resulting in furtherreduction of Nox emission, while CO is still practically eliminated.

The sixth embodiment as illustrated in FIGS. 9 and 10 shows a confinedcylindrical air guide aperture 16, with FIG. 10 being the same view asFIG. 8 in the fifth embodiment. Several vortex fins 17 project into theair guide aperture 16 closer to the second extremity 3. Vortex slots 18fill the interstices between the vortex fins 17. The force of thenaturally aspirated rising air through the vortex slots creates an areaof helicoidal vortex air currents in the secondary combustion air. Thelow-flow velocities of vortex air currents in this area further entrainthe fuel-air premix and improve combustion. As a consequence, COemissions remain practically eliminated (as in the prior embodiment),yet NOx emissions are further reduced.

FIGS. 11 and 12 completely illustrate the sixth embodiment of FIG. 9with the view of FIG. 11 rotated 90 degrees on the vertical axis., Theseviews are included to more clearly show that air guide 15 is hollow andincludes an opening closer to the first extremity 2.

One skilled in the art may of course proportionately scale the variousorifices, interstices and structures to increase or decrease the amountof input fuel and resulting output Btu power.

FIGS. 13 and 14 illustrate a multiple burner head of the seventhembodiment. FIG. 14 is the same view as FIG. 10 of the prior embodiment.As seen in FIG. 13, a lower fuel feed fixture 11B and an upper fuel feedfixture 11C are attach to a fuel feed bracket 11A. The amount of excesscombustion air in this embodiment can also be adjusted. Intake holes inan upper choke disk 13A are aligned through rotation over the intakeholes in a lower choke disk 13B. As illustrated the intake holes arefully aligned and opened.

FIG. 15 and FIG. 16 illustrate the seventh embodiment with the additionof external vortex fins 19. FIG. 16 is the same view as FIG. 14 of theprior embodiment. The external vortex fins 19 protrude into a tertiarycombustion air flow between the outside of the cylindrical air guide 15and the combustion cylinder inner wall 4. A further complimentary areaof helicoidal vortex currents result in the cooler tertiary combustionair. Lower combustion temperature further reduces NOx emission.

FIG. 17 and FIG. 18 illustrate an eighth embodiment with the burner headraised in the cylindrical air guide 15 such that the nozzle cap slots 10are closer to the second extremity 3 and outside the cylindrical airguide 15, with FIG. 18 being the same view as FIG. 16 of the priorembodiment. In this embodiment, the flame thereby spreads wider incloser proximity to the combustion cylinder inner wall 4. Flameentrainment with the slower and cooler airflow velocities of thehelicoidal vortex currents in the tertiary combustion air furtherminimize NOx emissions.

FIGS. 19 and 20 illustrate a ninth embodiment of the invention. In thisembodiment, similar to the embodiment of FIGS. 17 and 18, the nozzle capextends beyond the cylindrical air guide 15. However, in the ninthembodiment, the nozzle cap slots of FIG. 18 are replaced by a pluralityof nozzle cap holes 21. In addition, the nozzle cap 9′ is conicalinstead of hemispherical. The nozzle cap 9′ has a nozzle cap lip 20 thatprotrudes from the air mixer body 6. The nozzle cap lip 20 produces apattern of turbulence with a curvilinear retrogradation without theaddition of a turbulence disk 14 to the air mixer body 6.

In each of the embodiments of the invention, NOx reduction is achievedwithout use of devices such as laterally injected combustion air forminga secondary torroidal recirculation zone in the combustion cylinder 1further downstream of the primary combustion area. In addition, COemissions are practically eliminated.

While the present invention has been described in connection withvarious preferred embodiments thereof, it is to be understood that thoseembodiments are provided merely to illustrate the invention, and shouldnot be used as a pretext to limit the scope of protection conferred bythe true scope and spirit of the appended claims.

1. A fuel burning device, comprising: a tubular combustion cylinder openat opposing first and second ends; a fuel inlet pipe having a first endextending through said first end of said combustion cylinder partiallyinto the combustion cylinder and a second end extending outside of saidcombustion cylinder; a hollow air mixing body having a proximal end incommunication with said first end of said fuel inlet pipe, a distal endof said air mixing body having a hemispherical nozzle cap with aplurality of slots therethrough; an orifice connected between saidproximal end of said air mixing body and said first end of said fuelinlet pipe, said proximal end of said air mixing body having a pluralityof air inlet holes, said air mixing body being structured and arrangedat said first end of said combustion cylinder so that when fuel isburned, a naturally aspirated unregulated, turbulent forced air effectdevelops that increases the pressure at the plurality of air inlet holesso as to reduce CO and Nox emissions from the combusted fuel dischargedat said second end of said combustion chamber.
 2. The fuel burningdevice as claimed in claim 1, wherein there is a primary ignition ofsaid fuel at said slots of said nozzle that creates a circular patternof flame adjacent to an inner wall of said combustion cylinder.
 3. Thefuel burning device as claimed in claim 1, further comprising apositioning bracket connected to an exterior surface of said combustioncylinder and to said second end of said fuel inlet pipe, said bracketbeing adjustable to move said air mixing body toward said second end ofsaid combustion cylinder.
 4. The fuel burning device as claimed in claim1, further comprising a choke adjuster shaft connected between saidorifice and said fuel inlet pipe said shaft being adjustable to slow thespeed of combustion gas through the combustion cylinder.
 5. The fuelburning device as claimed in claim 4, further comprising a turbulencedisk connected to an exterior surface of said air mixing body, saidturbulence disk creating a first zone of turbulence above the turbulencedisk in a direction of combustion gas exit and a different second zoneof turbulence below the turbulence ring so as to create negativepressure at said plurality of nozzle cap slots, so that CO ispractically eliminated and NOx emission is reduced, when the fuel iscombusted.
 6. The fuel burning device as claimed in claim 5, whereinsaid second zone of turbulence has a curvilinear retrogradation pattern.7. The fuel burning device as claimed in claim 5, further comprising ahollow cylindrical air guide connected at a first extremity to saidsecond end of said fuel inlet pipe, a second extremity of said air guidehaving an air guide aperture, an exterior surface of said mixing deviceand an interior surface of said air guide defining an area of secondarycombustion.
 8. The fuel burning device as claimed in claim 7, furthercomprising plural vortex fins projecting from said air guide at saidsecond extremity and toward said aperture so as to form a respectivevortex slot between an adjacent two of said plural vortex fins, a forceof naturally aspirated rising air through said vortex slot creatinghelicoidal vortex air currents in said area of secondary combustion. 9.A fuel burning device, comprising: a tubular combustion cylinder open atopposing first and second ends; a fuel inlet pipe having a first endextending through said first end of said combustion cylinder partiallyinto the combustion cylinder and a second end extending outside of saidcombustion cylinder; a burner head connected to said first end of said.fuel inlet pipe; an orifice connected between said burner head and saidfirst end of said fuel inlet pipe, said burner head being structured andarranged at said first end of said combustion cylinder so that when fuelis burned, a naturally aspirated unregulated, turbulent forced aireffect develops so that combusted fuel discharged at said second end ofsaid combustion cylinder has reduced CO and NOx emissions,
 10. The fuel,burning device according to claim 9, wherein said burner head comprisesa hollow air mixing body having a proximal end in communication withsaid first end of said fuel inlet pipe, a distal end of said air mixingbody having a hemispherical nozzle cap with a plurality of slotstherethrough.
 11. The fuel burning device according to claim 9, whereinsaid burner head comprises a hollow air mixing body having a proximalend in communication with said first end of said fuel inlet pipe, adistal end of said air mixing body having a conical nozzle cap with aplurality of holes therethrough, said nozzle cap having a lip whichprotrudes from said air mixing body.
 12. A method of reducing carbonmonoxide (CO) and oxides of nitrogen NOx emissions, comprising the stepsof: positioning a burner head nearer a first open end of a combustioncylinder surrounding said burner head than a second open end, so that anaturally aspirated, unregulated, turbulent forced air effect develops;combusting an air/fuel mixture exiting from said burner head betweensaid burner head and an inner wall of said combustion cylinder;discharging the combusted fuel from said second end of said cylinder;using the forced air effect to increase a pressure at air inlets of saidburner head to reduce CO and NOx emissions due to the increasedpressure.
 13. The method of claim 12, further comprising the stepplacing an orifice adjacent said burner head to produce about 25,000 Btuat 11 inches water column supply pressure for propane gas.
 14. Themethod of claim 12, further comprising the step of adjusting a bracketconnected to an outside surface of the combustion cylinder to move theburner head closer to the second end of the combustion cylinder, whichfurther increases the pressure at air inlets of the burner head so as tofurther reduce CO and NOx emissions.
 15. The method as claimed in claim12, further comprising the step of adjusting a choke adjuster diskconnected through a choke adjuster shaft to a fuel inlet area of saidburner head to create a venturi effect in the combustion cylinder, soas, to slow down a speed of combustion gas through the combustioncylinder to still further reduce Co and NOx emissions.
 16. The method asclaimed in claim 15, further comprising the step of attaching aturbulence disk to an exterior surface of said burner head to create twodifferent zones of air pressure.
 17. The method as claimed in claim 16,wherein a first one of said zones is above the turbulence disk in adirection of combusted fuel discharge and a second one of said zones isbelow the turbulence ring.
 18. The method as claimed in claim 17,wherein the burner head comprises plural slots in the first zone, sothat a pattern of turbulence with a curvilinear retrogradation developsin a secondary combustion air, upstream, in said direction of combustedfuel discharge, of an ignition area of said plural slots between saidexterior surface of said burner head and an inner wall of saidcombustion cylinder.
 19. The method as claimed in claim 18, furthercomprising the step of inserting a hollow cylindrical air guide intosaid combustion cylinder, between said burner head and said inner wallof the combustion cylinder, so as to define a secondary area ofcombustion between an inner wall of said air guide and said burner headand creating a tertiary area of combustion between an outer wall of saidair guide and said inner wall of said combustion cylinder.
 20. Themethod as claimed in claim 19, further comprising the step of creatingvortex air currents by placing air vanes into the air guide, said vortexair currents substantially eliminating Co emission and further reducingNOx emissions.